Sony FE 55mm F1.8 ZA Carl Zeiss Sonnar T* lab test report

The Sony FE 55mm F1.8 ZA Carl Zeiss Sonnar T* is one of the first lenses for Sony's fledgling full frame mirrorless system, and designed as a fast 'normal' prime to complement the Sony Alpha 7 and 7R. However at around $999 / £900, it costs several times as much as the 50mm F1.4 options for DSLR systems. So what exactly are you paying for?

With our Sony Alpha 7R review well and truly underway (with luck and a following wind it should be finished in a week or so), here we're looking at one of the lenses we think buyers of this compact, high resolution full frame camera are most likely to consider. The other is the compact FE 35mm F2.8 ZA Carl Zeiss Sonnar T*, and we'll aim to bring you a report on that lens shortly, too.

In this 'Lab Test report' we're publishing full lens test data (as usual prepared for us by our collaborators at DxOMark) in our unique lens data widget, and presenting our own analysis of what it all means. This is a new article format, which we'll be using from now on to help cover more lenses than we've been able to in the past. It will complement, rather than replace our in-depth reviews, which we'll still be producing to cover the most interesting lenses on the market.

Full test results on DxOMark (and other recent reviews)

Our lens test data is produced in collaboration with DxOMark. Click the links below to read DxOMark's own review of the Sony FE 55mm F1.8 ZA Carl Zeiss Sonnar T*, or see other recent reviews on the DxOMark website.

Does anyone have any experience with extension tubes and image fogging with Sony A7R & Zeiss Sonnar 55mm 1.8. ? I am using Meike tubes. When used individually either the 10mm or 16mm tube gives an acceptable image but when added together (26mm) the image deteriorates significantly with severe fogging. I am wondering whether this is perhaps an issue with light behaviour inside the tubes or something to do with lens geometry. I can't think that poor connections between the tubes would cause fogging.

Aha, after posting this I read around the issue and found the solution was to scrape around the inside of the tubes with a hack-saw blade sideways, to roughen and cut grooves into the plastic lining. The image is now perfect, crisp and clear. I am in disbelief that someone would go to the lengths of designing, manufacturing and marketing a produce with such a fundamental and easily solvable problem.

Aha, after posting this I read around the issue and found the solution was yes, believe it or not, quite simply to close your eyes and scrape around the inside of the tubes with a hack-saw blade sideways, to roughen and cut grooves into the plastic lining. The image is now perfect, crisp and crustal clear. I am in total disbelief that someone would go to the lengths of designing, manufacturing and marketing a product with such a show-stopper of a problem. Images before and after the violation are attached here:https://dl.dropboxusercontent.com/u/76319093/Image%20before%20%26%20after%20roughening.zip

Hi can somebody help me make a decision?I have A7R with LA-EA4 adapter. I only have a 35mm minolta for prime lens which I use indoors. I want a 50~55mm prime lens.

I'm stuck between Minolta 50mm f/1.4 RS vs this: FE 55 f/1.8 CZ-The AF of LA-EA4 is very fast, I would guess that despite the fast auto focusing of the CZ lens, the old A mount lens would focus just as quick.-The sharpness and distortion wise, the CZ seems to have advantage.-At low light, despite light loss from LA-EA4 transparent mirror, the larger aperture would compensate some what.

At the moment, I'm not quite sure what I get from the CZ lens by spending extra 500$.

I find it amazing that there are some people here that are so negative about the performance of this lens. They keep on ranting about how big, heavy, expensive and bad it is. The truth is very simple; any way you look at it, this lens delivers astoundingly good image quality in combination with a Sony A7r camera body. There's simply no way you can deny that. If a lens gives me that kind of performance, I'm willing to pay for it.

Big and heavy, seriously? The A7r with this lens fits in a very small camera bag. If you think this is big and heavy, you should use a fixed lens compact camera like the RX1 or RX100 and stop crying in this thread. Or try a lens like the Zeiss Otus or Sigma 50mm f/1.4 Art on a Nikon D800E body for similar image quality. O well, I guess some people alway feel the need to complain about something. If I had the money for it, you'd have to pry this A7r Zeiss 55mm combo from my cold, dead hands.

I do not doubt the optical quality of the lens. But it seems that despite eliminating the mirror box and having the lens sit a lot closer to the sensor plane, Sony and Zeiss are not able to make the lenses smaller or faster.

F1.8 is not fast for a 55mm. And the FE 1.8/55 is not small by any standards. Personally, I will rather have either a larger 50 that is a F1.4, or a really compact 50mm F2.8. A really big standard lens that isn't fast is simply a lousy compromise. Given the advances in sensor technology and the more than usable high ISO settings in contemporary cameras like the A7, I'll probably opt for the latter -- a slow, but optically exceptional and compact 50. Afterall, gone were the days of rewinding with the film leader out so I can swap between Velvia 50 and some ISO 800 film.

The lens I miss the most fro the film days was the Contax MM mount Zeiss 50mm F1.4 Planar T*. It/s 3/4 the size of this 1.8/55 and it was $350 (new).

And it was 3/4 the optical quality of this one. Check the numbers, it beats everything on the market. Except Otus. Don't see people complaining about that one.... http://www.dpreview.com/reviews/lens-compare-fullscreen?compare=true&lensId=sigma_50_1p4_a&cameraId=canon_eos5dmkiii&version=0&fl=50&av=2.8&view=mtf-ca&lensId2=sony_zeiss_fe_55_1p8_za&cameraId2=sony_a7r&version2=0&fl2=55&av2=2.8

No, I get it. But, what I am saying is that similar optical performance -- even illumination, aberations and resolving power -- can also be done in a much smaller package and a similar number of elements in a hypothetical 2.8/50 Planar T*. Add one more element (8 elements, 6 groups) and you can do an Apo-Planar. And either will be about 3/4th the length and 2/3rds diameter (it's be about 1/2 the front element diameter, but I am being a little generous on the focus motor and other stuff)!

Oversized isn't really true - it's longer but thinner than a typical 50mm 1.4 like Canon or Nikon. Comparing it's weight to the same is not quite fair since it's worlds above those lenses. You really have to compare it's mass to the Otus or a Leica 50mm. Then it's very reasonable size and weight.

It's not heavy at all. And the A7 isn't exactly a "little" body. Are you sure you're talking about the same lenses and cameras? Of course it's too short for portrait/mid-tele. That's because it's a normal prime. What were you expecting when you read "55mm"?

ABSURD ! I mean, what's WRONG with these guys? One could compete, just about, with this, using a plain old Minolta 50/1.7 for like $50. Either through A 2 E adapter, or choosing an A-mount A99 instead.Sony's out to lunch with the E-mount prices. It's just plain weird.

Show me the MFT chart or test result of Minolta 50/1.7 on A7R. The Zeiss 55/1.8 is almost as good as Zeiss Otus 55/1.4 for 1/4 (or 1/5 if you get the $200 off discount) of the Otus' cost. How is that absurd?

You have to appreciate it's performance to understand. It's not just worlds sharper, it lacks any of the nasties that a Minolta 50/1.7 or even a Nikkor AF 50/1.4 have wide open. It even beats those lenses when stopped down in noticeable ways.

So I would say, no. One can't compete with the Rokkor 50/1.7. The difference is noticeable. If you are one who doesn't really appreciate those particular things, you won't buy the 55 /1.8.

I purchased Sony Alpha A7R with (Zeiss lens 55mm f1.8). I am confused about E-Mount and FE-Mount. If I purchase new lens will I ask for FE-mount? or E-Mount? from what I understand E-mount is for NEX lenses (APS-C E-Mount lenses) am I understanding this correctly? Thanks.

FE and E-mount have the same mount, meaning the same bajonet, so they are compatible with adaper or anything. The only difference is that FE lenses cover the full frame sensor area, whereas E-lenses only cover APS-C.Your A7r can take both E and FE lenses, but if you attach an E-lens it will only (automatically) use the center of the full frame sensor, reducing the resolution to 15 Megapixel. The View on the viewfinder and Display will automatically be adapted so actually others than the lower resolution you won't notice a difference between E and FE lenses in use.I use all my older E-mount lenses on the A7r now without issues, but in your case I wouldn't invest into E-glass now, better concentrate on FE.

All lenses are E-mount. The mount is 'E'. 'FE' is an additional label they put on lenses that cover a full frame sensor. Lenses without the label do not. Because when E-mount first came out when there was only APS-C sensor sizes, having a label to show they were APS-C was redundant. Conversely, with A-mount, APS-C lenses are labelled 'DT', because APS-C A-mount lenses came out in the digital era, while the original lenses were all from the (FF) 35mm film era.

With German Carl Zeiss brand built quality and 2x~4x $998 price tag, this 50mm F1.8(only) lens IQ has to be top quality than the cheap Canon and Nikon 50mm 1.4/1.8 lenses.

Oh no... the vignetting of this CARL ZEISS lens only go off totally at F8.0, it was much worst than the cheap and good Nikon 50mm F1.8G lens which go off totally after F4.0. That was pretty bad and what a shame.

? So you want to find one parameter where things are a bit off and you criticize? Have you actually compared the results between the two? The Zeiss is in a class of it's own. The only Nikon that approaches it is the new 58mm 1.4 G at - $1800.

No not aware, but interesting piece of bull your are spreading this way given the lens is dust/weather sealed...The only note I could find which may have triggered your comment on this is from someone who mentions he had dust in his old 30 year old Canon 50 fd 1.4 lens which he has as an intermediary to this lens going on offer. His comment is a bit oddly written so you could accidentally read it like he had problems with the sony 55/1.8 (which he does not have)

Wow! What a great lens, according to the results of this review. Head and shoulders above the competition. One might even say there is no competition.

I have saved a few thou I'd like to spend to acquire more modern cameras than I now own and the Sony A7s seemed to be, theoretically, at least, what I wanted in a digital camera. This lens' results, on the A7 and A7r, reminded me of another lens/camera pair I had read the results of on DxO: the Sigma 18-35mm f:1.8 Art lens mounted on APS-C Nikon 7100. Yep, the sharpness curves could be overlapped almost exactly!

So, I'm off to buy a new K-3 Pentax body with microprism focusing screen and big, bright optical viewfinder and the Sigma, to replace my K10D and Pentax-DA 16-45mm F:4.

Same resolution results as the Zeiss on an A7r but in a crop sensor, with similar low noise, better RAW formats and more optics available, including some Pentax glass I already own.

every camera model tests lenses differently using different standards. so lens tests are not directly comparable if the camera models are different (even of same pixel count, or even same sensor, if anyone doesn't already know).

Because the Zeiss will likely be as good (and perhaps better) as the 50L at F1.8, while the Canon 50F1.8 is not and is not even close. I am thinking any new Canon 50F1.8 is going to weigh significantly more than the nifty fifty, have better IQ but doubtful it will be as good as this Zeiss, and have a price tag closer to the Zeiss. Also, Canon does not have a FF body that comes close to the weight of the Sony - nor one that is 36mp. Add the saving in weight of the body AND the lens - and it is significant.

well, I read sooooo many times from the sony-haters that the ZA lens have NOTHING to do with zeiss...that sony just bought the licence for the blue logo to put on their glass and bla bla bla...suddenly when the ZA glass gets TOP rating, its not sony anymore, its again Zeiss :D ... you got to love em haters :)

some shallow person at Sony loved Zeiss too much but if there is any rational in the decision to license a foreign brand it should be that Sony see no chance for them even in the far future to build their own brand as a quality lens maker.

very true. Sony fanboys butthurt. does Sony own Zeiss? NO ! that's why they contract Zeiss to make lens for them because they cannot make their own design. they cannot even think how to better design lenses after buying Minolta.

In my experience, expensive lenses are expensive because of superior quality of construction as much as better optics. In a way this is a good thing, because the photography fanboys who switch brands because of peer pressure don't loose too much if a lens has a one or two year life expectancy as they will be moving on. Third party lens makers exploit this market sector.

The Sony lenses, and especially the Sony/Minolta G's / Sony ZA's are built to last ( the number of 20/25 year old Minoltas still in use is amazing ) and are not far short of Leica/Schneider/Voigtlander industry standard setters in construction quality.

Get Roger Cicala to strip down the FE 55mm and you'll find that beauty is more than skin deep as he found with the A7R camera.

I have this lens on the A7 and I will so only one thing 'Stunning', equals and and probabaly betters the leica summilux 50 asph on the leica M (240)Expensive!!!! the Leica costs £2700 so it is cheap by comparison

Sony E-mount is definitely a better mount than Leica M. Leica used to be the king but was kicked out of the market by some short Japanese dozens of years ago. it's not approperate to use a virtually non-existence as reference.

of course it is relevant as the leica M an the 50 lux are the nearest equivalent in size and performance and both are the only FF mirror-less cameras on the market. AS I own both I do feel that I can make a comparison.

What is meant by "all-metal construction" in the "Materials" section of the specifications? I find it difficult to believe it can have such a similar weight to the Canon 50mm f1.4 which is almost entirely plastic without also making quite extensive use of plastic.

Sony Zeiss lenses are not true Zeiss lenses. The Panasonic Leica m43 lenses are neither designed nor made by Leica, but they are manufactured using equipment and quality control methods approved by Leica. I don't know what kind of requirements must be fulfilled before you're allowed to put the Zeiss logo on a lens, but it's probably something similar.

@jennyrae, you don't know what you are talking about. I guess you haven't shot using G lens by Sony and "ZA lenses are designed and manufactured by Sony in Japan, while Zeiss will ensure that certain design and quality parameters defined in a collaboration of Sony and Zeiss are met."

@heaven. G lens designed by Minolta. G lens=rebranded Minolta lens. do your homework. only job done by Sony is acquire rights to them products but not design them. with Sony branded Zeiss lens is same also but not make Sony real makers of the lens.

if there was something that Sony made as achievement, it is sensor development. that's it. but do not take too much Sony weed to think everything is made by Sony is excellent.

it do not bother me. just say that give credit to where it is due. some people get defensive when I say statement that Sony do not produce or make their own lens which is truth. the bother come from Sony fans, not me. they claim Sony make great lenses which is false information. they have great lenses made for them but not they made. attempt made by them has been not to standard by Zeiss. not refer to where it is manufactured but who made lens like if it was Zeiss or not.

if you read, I did not say anything bad about lens but some people get upset when I not give credit to Sony because of lens but give credit to Zeiss instead. I have logical reason to do so because company made the lens and not Sony.

@jennyrae, I believe the lens is 100% design by Sony, and Sony has licence to use Sonnar lens designs, and qualities are control by Zeiss since they dont want Sony to ruin their brand. You will probably cant find a lens element design similar to this in the Zeiss range. Plus I dont think Zeiss are expert in lens AF. Perhaps Sony and Zeiss are work together to deliver the Zeiss AF lenses. Who knows. If what you saying is true about all the credit should be Zeiss then non of the good camera on the market should be credited by the brand, as the component are not design by that brand. Take the Nikon D800E for example, I dont think the board memory chip are design by Nikon, mostly like some taiwanese IC companies, you see why it has good continueous shooting buffer, its should credit to the IC chip company not Nikon? . Lastly as a consumer, why you so care sony fanboy cheering at their brand? well only one logical answer is you not a sony fanboy :)

I would be so curious to see how Sigma fare with FF to make lens especially if they can do the 19, 30 and 60mm. To be compete against Sony with Zeiss glasses at lower price. That would be rather interesting. Its good to have more option of what brand you want to choose the lens. Lacking option isn't that good though.

So little choices and such a big difference in price. I would have to make money on something this expensive. This is a 55mm $1000 lens! Personally I don't make money on photography to invest in such product.

'You get what you pay for' that's my problem with Sony, they either offer these very expensive Ziess lenses which are very good and sharp or you have a limited Sony own lenses which are basically 'Tesco Value' lenses.

Probably one of the sharpest optics by Zeiss and the price is in the proper range for such glass and brand. But introduced on mirrorless body system not on high end DSLR? I thought these two mirrorless cameras aimed at advanced user. For an advanced user this lens becomes just a 55mm lens, at not even high but astronomical price.

You forget unlike Canon and Nikon who cripple their mirrorless offerings and wonder why they can't sell them Sony has turned out very useful mirrorless cameras. In this case the bodies are $1700 and $2300 so $1000 for prime that can be used for portraits etc. is not un reasonable. Its and FE mount lens.. not targeted at the AXXXX or NEX users..

These two cameras came out at the same time, the 7R is not an upgrade, 7R cost about $600 more. And only one lens made for both cameras - 55mm at $1000. It couples with 7R but for people getting a cheaper 7 model, $1000 for 55mm lens could be a bit unreasonable.

lem12... I don't think anyone would argue that if you're going to spend money on a body *or* a lens... it's going to be a lens. That said, it requires commitment to a brand. The A7 has a 24mpix, full-frame sensor that compares favorably to any DSLR offering similar. Granted, the sensor isn't everything, but it's a bloody good start.

I have one, and what would I change? Get rid of the gimmicky junk that is best done post-processing (read: not at all) in a future version. Make the bottom plate tougher as it feels like a big lens might break/crack it. I have the battery grip, which is very good/strong.

Rocky Mtn Old Boy, Personally I think Sony makes one of the best sensors on 35mm frame market. And for such giant like Sony it's easy to pop another great line of electronics. I have no doubts here. So that places A7 on the level with Canon and Nikon DSLR's in similar price range. The problem I see here that Sony could pop cameras faster than make enough lenses for them. And these electronics get upgraded so quick that the cameras like A99 is already behind by its sensor performance and oddly more of a camera than these two. Considering all this paying a $1000 for 55mm lens for A7 is a bit unreasonable.I wish I could! 8)

lem12... on those points I tend to agree with you. I suspect that we will see this very same 55mm lens come out in the A-mount soon enough.I am not sure why the mount change (to E) on the A7, though if I had to guess, it's because the old A-mount is restrictive in its design.

But this is not really considering your point, which is why $1000 for a 55mm? Well, if you look at the Canon and Nikon offerings... ok, well neither of those brands has anything even close (according to DX0Mark) even though they both have standard lenses over $1500. Apparently the Nikkor 58mm is atrocious, and while the Canon 50mm 1.2L is over a stop faster, its IQ is far less. In fact, the only lens that is really in its league is the $4000 Otus... which is only marginally better.

Again according to DX0, the A7 has a sensor and associated IQ ranked in the top 10 (along with the A7R and two fixed lens Sonys).

In my books, that earns a decent lens. And welcome to diminishing returns. ;-)

You need to watch out for vignetting at lower f stops like around F1.8 or F2 or F2.8 or so. That is very good lens I must say, very high level of sharpness but distortion is fairly significant that may be common through Sony lens even incorporated with Zeiss glass. I found that Sigma lens has a lot less distortion when combined with Nex 7 to compare to Sony fixed focal lens. Sony need to improve in manufacture over lens to have less distortion and vignetting that would be nice if they do so.

Your comment is rejected by me for reason because you have not pay attention closely to distortion and vignetting. I saw DxO and can clearly see some distortion there, thats a bit of worry for that pricing lens. Sigma E mount 19, 30 and 60mm have a lot less distortion than Sony normal E mount lens according to SLRGear review.

If you're going to compare with APS-C lenses, the FE 55 has no distortion on a APS-C crop sensor - the distortions are in the extreme corners of a FF sensor, and comparable with other FF 50s (e.g. it's less than the Nikon 58/1.4 G).

" Sigma E mount 19, 30 and 60mm have a lot less distortion than Sony normal E mount lens according to SLRGear review"

I didn't say there was no distortion, I said less than the Sigma 60mm and practically no distortion on APS-C (the Sigma's are after all APS-C lenses at best...), the latter confirmed by DXO and SLRGear.

SLRGear did not even test the 60mm and shows between 0.19 and 0.5% distortion for the 19mm and 30mm on APS-C, just 0.1% for the FE 55mm on APS-C. Vignetting of the 55mm was also tested to be lower on APS-C than both those Sigma's at SLRGear. DXOmark also shows both distortion and vignetting to be lower on the FE 55 on APS-C, than any of the 3 Sigma's.

@naththo: "Sony need to improve in manufacture over lens to have less distortion and vignetting that would be nice if they do so."

Sorry, I don't know where did you get this... Distortion and vignetting has nothing to do with "manufacture" - these are pure design compromises / tradeoffs / limitation, generally unaffected by production variation.

TrojMacReady, Yeah now I am aware that SLRGear did not test 60mm which is a pity but at least I am happy with this lens on Sony Nex 7. Its pretty good anyway and excellent value for money I must say. Its important to compare bronze to gold. Choose which one you want. Cheap sigma or very expensive Zeiss, take your pick. I think it will take a while for Sigma to make new lens for the FE mount series. Probably say few years time. While Zeiss is out already like these.

ZeevK it might be to do with quality control problem as well that could be the culprit. But review tells the truth regarding to resolution, distortion, vignetting, etc. Other than that I took risk to buy 60mm Sigma and still very happy with quality overall because that SLRGear has not yet review that though.

straylightrun, you made me laugh anyway :P

Heaven is for real: Like one of comment I read came from quezra is definitely correct. 10 out of 10 points for quezra.

One more thing while waiting for Sigma to make new FE lens. I don't think Photography around here would wait patiently for that. Sony and Zeiss are doing good job to do that straight away and is available already. So most photography here would prefer to buy new lens like these that are available now than waiting for few years for Sigma to come out. I am waiting for 24-70mm to come out in February but not available in Australia yet. $1500 is going to be about that for here.

Actually someone may have done unofficial review on that Sony with Zeiss glasses lens of 24-70mm F4. I better find it. As I want to be able to compare against this current kit lens I have on A7. (Btw this kit lens does good job on F8 aperture though).

http://www.slrclub.com/bbs/vx2.php?id=slr_review&no=383 Thats the one I found for 24-70mm lens. Pretty good but corner sharpness look so so so far though but it possibly he might have had prototype copy or bad copy.

There is another one here: http://www.the.me/a-worthy-24mm-zoom-the-zeiss-vario-tessar-24-70mm-f4-for-sony-a7r/

But I think that lens will still be better than Kit for the quality of it though. Of course using higher f stop is better off with.

@DpreviewDxo also reviewed this lens on nex-7. I don’t understand how it can get a phenomenal 29/36 mp resolution on the A7r while only getting 15/24 mp result on the Nex 7. I understand the nex 7 has anti aliasing filter, but it wouldn't make that big a difference would it? I see the very cheap canon eosm 22mm lens scores a relatively better 13/18 mp. Please help me understand.

I am not 100% sure I understand the DxO rating, but I would expect anti-aliasing filter to eat away substantial amount of effective Mpix resolution. At the same time - the Nex7 has larger pixel density than the A7R (though not by much).

One way to another - the 55/1.8 seem to be an excellent lens with lovely rendition. I just hope that more Zeiss primes with this quality are coming for the A7/A7r cameras.

The NEX-7 sensor seems to have microlenses (and possibly complete pixel design) that reacts badly to any oblique light. You can find test after test of fast or wide-angle lenses that do poorly off-center.

I don't look at the dxo site much but if I recall correctly the same lens always gets a higher rating on full frame than on aps-c regardless of make. (justs checked and the Nikon 58mm f1.4 is has a higher rating on the 610 than on the 7100)

As to the Sony lens. Nice short portrait lens on aps-c but 55mm is too long for a standard lens on full frame for me personally. I never liked 50mm never mind 55mm when I shot film.

Yeah, all Sony CMOS sensors have micro-lenses... they are just calibrated differently. Sony has only ever made one 24 MP APS-C mirrorless sensor, and I wonder if a simple recalibration of the micro-lenses might be all it takes to get some amazing performance out of both legacy lenses and FE lenses. Hopefully the 7 successor will see this

Considering that 36mp cropped to APSC is something like 16mp, the fact that it gets 29mp on FF and 15mp on ASPC seems to make sense. It's about half for both cases, which is what you'd expect if you cropped your 29mp-sharp FF image to APSC size.

The "circle of confusion" of any lens aberrations are the same on both sensors, but the FF sensor has pixels that are spread out more with fewer pixels falling into those circles. Lenses are therefore sharper on FF, at least in the common central portion of the image.

@balios. Confusing part is nex7 is 24mp sensor but only resolve 16mp effect. bad part for nex7 is no lens made for it or nex7 is just bad design. My opinion is nex7 is enlarged 16mp sensor or false 24mp. Can be reason why best lenses struggle to even reach 20mp. With camera sensor limit, lens resolvepower become limited.

@Andrew booth, that did not explain why other APS-C with same sensor size and pixel size size resolve better. can you explain why 55/1.8 resolve less on smaller size sensor? 55/1.8 should perform better on APS-C because of smaller field of view and cropped corners, not opposite. that do not explain why lens resolution on NEX7 is stuck at 16MP and not 24MP. if this was A7r camera, I understand reduction of pixels due to cropping of the sensor by 1.5x equal to 24MP, but APS-C NEX7 is native 24MP but resolve only 16MP?

If this Zeiss is resolving 29mp on the A7r (36mp, no AA filter), then the lens is the limiting factor at 29mp on FF sensors. If you put that 29mp-sharp FF lens on a APSC camera, then it can't resolve more than about 15mp. Even though the sensor is 24mp, that extra detail won't be sharp

15mp is very good for an APSC camera, that's about equal to the Sigma 35mm Art lens which everyone is raving about. Its better than all my Canon L lenses on crop sensor (but not on FF).

What this means is that having an APSC sensor with more than 16mp has diminishing returns. If you want to resolve more than 16mp, you should really look at getting a FF camera. To make full use of 16mp+ APSC sensors, you need to start looking at expensive lenses like the Zeiss 50mm Otus (21mp on 24mp ASPC, $4k) or the Zeiss 135mm APO (20mp on 24mp APSC, $2k).

@balios. Thank you for explanation. However the otus comparison make it a bit more difficult to comprehend especially if ff camera comparison make it appear otus and fe resolution is very close. My suspicion is nex7 can be culprit. To be sure of result I think nex6 or nex7 successor is used also and see if resolving for nex camera is really limited to 16mp or can be pushed to 20mp. Agree that lens is really excellent and look to be close to art lens. But just wanted to be sure if lens can resolve more with better apsc body. This is because I was not really impressed with nex7 camera eversince. I wait to release of new sigma 50 art.

OK, everybody acknowledges the sharpness (score) is partially because of the A7R 36mp sensor. But what about A7? I think it's more fair to compare this FE 55/f1.8 on A7 with 50/f1.4 on Canon 6D and Nikon D610. They are the most popular (affordable) FF cameras + standard prime lens bundles and the overall prices are in the similar price range as well.

Yes, I too wonder what the performance would look like on the A7. Why didn't they test that?

New boyz - if you select NEX-7 and compare to Otus on the Nikon D7100, you'll see a big difference on favor of the Nikon + Otus, but on the A7R the FE 55 and Otus are about tied. So, it's not as sharp on any sensor.

It has more to do with pixel density over the area the image itself is cast, smaller circles tend to be sharper (micro 4/3) than full frame image circles. In the end the result is what matters, full frame is less densely populated with pixels (often).

If we would measure purely resolving power, a microscope lens would obviously outresolve a large format lens.

Some people seem to forget that 55/1.8 + usable ISO 6,400 is still something like 1 stop brighter than the legendary Canon 50/0.95 - given what sort of film was available back then (and how expensive yet noisy ASA 400-800 could be). And 2-3 stops brighter than f1.2 lenses of the day - that weren't even nearly as usable wide open.

One of the notable things here is the light transmission -> T1.8. It almost equals many 50mm f1.4 lenses that usually have light transmission around T1.7. And this is due to the sonnar-design, that uses very few lens elements. This design is also reason why the lens appear to be a bit longer than traditional 50mm lenses. With DSLR cameras and short focal-length lenses it's actually impossible to use sonnar-design, and you are never going to see this kind of lens with current DSLR's, it's only possible with mirrorless cameras. This lens is an excellent example what optical designers can do when there is no stupid mirror and space that is requires to give limitations in design. Sonnar-design is also very known for creating very pleasing bokeh rendering - something that these charts can't even show.

I feel Sony is going to release nothing than outstanding lenses for this FF E-mount. The myth that Sony is not good at lenses is truly a myth for people who used A-mount Sony Zeiss and Sony G glass. These new FE lenses are so incredibly lightweight as well, much lighter than they look like. Product design couldn't be better as well in my opinion. This will be a winner system for sure, not for everyone, but for people who want to travel light but don't want to make any compromise with sensor size and picture quality. Pair this with a little RX100 in your pocket and you are set for almost everything...

It is to be remembered that while Sony produces the lenses mentioned here, the optical design comes from Zeiss, as do the requirements for quality control. And on top of that - Sony really is expected to produce excellent lenses on their own too - after all they have taken over the Minolta which had some excellent lenses in their line.

Hooray for Sony.A brilliantly sharp and well made lens for a small amount more than Canon's 2.8 IS offerings. Granted they are not a 50/55 but they are comparable prime configurations.

I hope this signals the beginning of a number of premium lenses from Sony. Considering that Fuji is currently setting the standard for optical excellence and fair pricing for their quality, I am sure that Sony have noticed the accolades for Fuji's line

More careful observation of results should dump down initial enthusiasm. In fact this lens is only great on FF. It is quite mediocre on APS-C and there's something in optical design or coatings which spoils color reproduction with filters (at least UV).

How do you come to the conclusion that it is only so-so for APS-C? The center is the sweet spot of highest performance and is what is used by the smaller sensor.The resolving power of the lens is measured to be extremely high in absolute terms..

In addition, DPR and DxO say the is one of the sharpest lenses they have ever tested so how does that make it mediocre?

Color reproduction? Lets see some facts that go beyond the typical color signatures of different lenses.

the center resolution is about 2400 at open, which translates to about 1550 on APS-C. it's about 1200 for Canon 50/1.8II tested on 7D which has about 8% higher pixel count per PH (than A7R cropped to APS-C).

so this is more like 1550 vs 1100 (ignoring many other factors so with error). the Sony one still wins by a large margin, not as large as many may think though.

and if center resolution translates directly into value, the new Sony should be 1550^2 / 1100^2 = 2 times more valuable than Canon or worth about 220 US.

This way: http://dl.dropbox.com/u/12196364/gallery/different/fe55isnotthatgreat.pngYou can check it for yourself: http://www.dxomark.com/Lenses/Compare/Side-by-side/Sony-E-50mm-F18-OSS-versus-Sony-FE-Carl-Zeiss-Sonnar-T-STAR-55mm-F18-on-Sony-NEX-7-versus-Zeiss-Carl-Zeiss-Distagon-T-STAR-Otus-55mm-F14-ZF2-Nikon-on-Nikon-D3200___745_0_1252_736_1242_801

As you can check, this FE doesn't seem better than SEL 50. In fact, I would prefer to have better central sharpness and not quite good edges to mediocre everything of FE 55 (on APS-C).

I do, and you not. See the screenshot above: Otus is close to excellent. If the center part of FE 55 was about as good as Otus I would call it very good. But, it is not. And it is even worse than SEL 50. FF glass needs less sharpness to be very good and it is the case: FE 55 has flat field of view and quite good resolution WO, which makes it a very good performer for FF. But, its resolution is not enough for APS-C, where it loses in practice to even SEL 50, not to mention the Otus, which is in its own league. So, switching from MF to A7r+FE 55 is not the best ever idea. On the other hand, switching from MF to A7r+Otus is quite reasonable (more reasonable than to D800+Otus IMO, thanks to EVF and much better LV implementation).

Cost does not increase linearly with quality does it yab? So your mathematics are some way off as usual. Don't become a math or economics teacher. We seem to be running out of things you might be good at don't we yab?

Emacs, are you seriously suggesting the Otus is the only lens that is 'good' and all other lenses are mediocre? The SEL50 is worse in the corners, and fractionally better in the centre. I can tell the difference in sharpness in the corners with either mounted on my 5N, I certainly cannot tell the difference in the centre - they are both superb. You are looking at a paper specification and equating 'slightly less' with 'mediocre' which is ludicrous. Get both lenses and shoot some actual photos and get your head unstuck from your theory bowl.

I do enjoy how people who were insisting on finding fault with NEX lenses are suddenly praising them when realising how good they actually are.

It is excellent on FF while the still besting the lenses purpose made for APS-C. This is a specious comparison. Much like saying your motorcycle is better than a car because it is faster and gets better mileage.This lens covers FF and thumps the competition. An APS-C lens can't cover FF and thus loses on the "edge resolution" front.

People always laud MF IQ. The truth is that many MF lenses were not as sharp as 35 lenses but then they never had to cover MF. This is precisely the case here but the lens in question still trounces the budget lens used in this false comparison.

@Yabokkie, this lens beats the others optically irrespective of whatever camera you put it on IF you can put it onIn the end, everyone wants great construction and excellent IQ and then wants to pick nits. The truth is that the new lens is superb but also the lenses we already have are fairly decent.

to be specific, there is no clear trend between cost and resolution that higher resolution can be achieved at no extra cost (there are some factors affect cost like very different design using more lens elements or more expensive ED glass that we can add to the final cost).

This looks like a "best in class" performance, probably better in just about every way than any of my about 20 old "fast 50s". It is just a pitty that it costs about 2.5X the combined total cost of all my old fast 50s (including a Canon FL 55mm f/1.2). The f/1.8 aperture isn't super fast, but old lenses don't have the greatest transmissivity, so I wouldn't be surprised if it lets more light pass than a lot of old f/1.4 lenses... especially old lenses with radioactive yellowing.

There are plenty of inferior fast 50s that people pay $600 or more for, and I think this lens should make reasonable people much more hesitant to do that....

this is DPReview but I think DxOMark should test all the lenses on one camera as far as possible for better comparison. say every lens on A7 or A7R besides its native mount cameras. should keep using the same camera even higher resolution ones are available.

This lens has only 0.1EV less transmission than the F1.4 otus, according to DXO. It's probably one of the best (the best?) low light setups out there - you get slightly more depth of focus, with practically the same transmission as F1.4 lenses, superb sharpness wide open and lack of mirror slap means you can get use shutter speeds (like in rangefinders). Then add a rather good high ISO performance on top of that. Looks fantastic.

"For the vast majority of photographic history a f2.8 50mm is "fast" and a f2 50mm prime is "very fast""

I think the recent technological lens and camera developments has made this sort definition a little outdated as the idea of "fast" as in a fast prime lens has now dropped, where the term "fast" is more aptly applied to lenses of F2 or greater aperture on primes. F2.8 just doesn't seem to be that "fast" anymore for a prime. Anything with a max aperture greater than F1.2, now goes in to the "super fast" category for primes. Of course, for zooms, F2.8 or better is still "fast".